Inherited Tendencies

Doctors focus on genes in the battle against breast cancer.

You're grateful for the piercing blue eyes and appreciate the good teeth, but not so much the weak chin and near-sightedness. What else have you inherited? For women with a family history of breast cancer, genetics - as it relates to cancer risk - can be a real and substantial worry.

To garner clues about a woman's familial risk of breast cancer and hints as to which preventive measures might be best, doctors sometimes turn to genetic testing. It cannot help everyone, but genetic testing can improve outcomes and sometimes alleviate the anxiety of patients whose family history leads them to believe that they are doomed to develop breast cancer or some other types of disease such as Alzheimer's and colon cancer.

How does it work?

Genetic testing can reveal whether a particular high-risk genetic mutation exists within a family. Experts believe that approximately 5-10 percent of breast cancer cases could be caused by a genetic mutation, which translates to about a 1 in 400-500 risk, says Denise Jeffery, NP-C, a nurse practitioner at Elliot Hospital's Breast Health Center who specializes in genetic testing.

If a health care provider suspects that a patient has a high genetic risk, genetic testing might be recommended, but "just having a mother or a first-degree relative who had breast cancer is really not enough to warrant genetic testing," says Bradley A. Arrick, M.D., PhD., section chief of Hematology/Oncology at Dartmouth-Hitchcock Medical Center in Lebanon and the Norris Cotton Cancer Center. Among the features that doctors look for within a family "are multiple cases of breast and/or ovarian cancer over multiple generations that [occur at a] primarily younger age of onset," Arrick says.

Typically, patients meet with a genetic counselor before undergoing testing. "Genetic counseling involves a full evaluation of the family history," Arrick says, and can also explain to patients "emotional risks, disruption of family interactions and insurance problems down the line" that might result from genetic testing. It should also make clear to patients that genetic testing does not always "give a yes or no answer. Sometimes the answer is somewhere in between," Arrick says.

One of the other main purposes of genetic counseling is to help identify appropriate testing candidates. To best confirm or rule out a mutation within a family, one or more family members who have had cancer should undergo genetic testing, not a family member who perhaps is worried that she might be next, but has never had cancer herself. "Every family may have its own unique mutation," Arrick says, so to get a good sense of whether an unaffected family member shares in the risk, doctors must determine "what the genetic basis is in that family, and the best way to do that is to test the people who actually had cancer," although the person who first sought the counseling might be tested later if a positive result is obtained in the relative, Arrick says.

Also, sometimes a person who has never been diagnosed with cancer is tested because other family members who have had a cancer diagnosis in the past are deceased or refuse to get tested, Jeffery says. Why people refuse to get tested is difficult to explain, she says. "There's a lot of fear" surrounding genetic testing, Jeffery says. "Some people really just don't want to know. I've seen several women that I have recommended have genetic testing but they prefer to come in and have their yearly mammogram and breast exam and they don't want anything to do with genetic testing."

Sometimes reluctance to be tested stems from wanting to avoid tough decisions: if the test returns a positive result, the patient might have to decide whether to opt for increased surveillance - possibly an alternating schedule of twice-yearly mammograms and MRIs, preventive medications or surgical procedures, Jeffery says.

Many of the patients who refuse testing believe that what they don't know won't hurt them, Jeffery says, but in reality, they are depriving themselves of potentially life-saving knowledge. Testing can be anxiety-provoking, for sure, but the results can help participants and their family members to be more proactive, Jeffery says. "Historically, there have been few examples in medicine where we could take steps to diagnose a cancer in its earliest stages or prevent it from occurring. Genetics has significantly changed the landscape. For those people who have genetic mutations patients have options that can significantly limit the risk." NH

Has the patient or any family member had bilateral breast cancer (breast cancer in both breasts) or twice in the same breast?

Have there been any cases of ovarian cancer in the patient or a relative at any age?

Is the patient of Eastern European Jewish ancestry? (This population has a much higher risk of genetic mutation than the general population, Jeffery says - about 1 in 40.)

What the future might bringTraditional radiation therapy for breast cancer patients can require many treatments - typically at least 10 and sometimes many more than that, says Kari M. Rosenkranz, M.D., medical director of the Comprehensive Breast Program at Dartmouth-Hitchcock Medical Center in Lebanon. That's a lot of trips to the hospital, over a period of weeks, for an unpleasant task.

But a promising new treatment currently being researched could make some breast cancer patients' lives a little easier. Single-dose intraoperative radiation is performed during breast cancer-related surgery rather than after and, as its name implies, only requires one dose. It is thought to be perhaps safer and certainly more convenient than traditional radiation therapy.

Single-dose intraoperative radiation focuses specifically on the tumor rather than sending radiation into the entire breast, but its targeted radiation is currently only a "theoretical benefit,"

Rosenkranz says. "Normally radiation to any part of the body is a once-in-a-lifetime thing," she says, so an unresolved concern is what would happen if the cancer recurs in the same breast. "Could you maybe get two separate bouts of radiation to the same breast if you had a [cancer] recurrence? Nobody really knows yet," she says.

So, mark this therapy as hopeful, but more long-term research is needed.

This article appears in the March 2011 issue of New Hampshire Magazine